On Tue, Aug 14, 2012 at 06:52:14PM +0100, Catalin Marinas wrote: > This patch adds several definitions for device communication, including > I/O accessors and ioremap(). The __raw_* accessors are implemented as > inline asm to avoid compiler generation of post-indexed accesses (less > efficient to emulate in a virtualised environment). > > Signed-off-by: Will Deacon <will.dea...@arm.com> > Signed-off-by: Catalin Marinas <catalin.mari...@arm.com> > --- > arch/arm64/include/asm/device.h | 26 ++++ > arch/arm64/include/asm/fb.h | 34 +++++ > arch/arm64/include/asm/io.h | 263 > +++++++++++++++++++++++++++++++++++++++ > arch/arm64/kernel/io.c | 64 ++++++++++ > arch/arm64/mm/ioremap.c | 84 +++++++++++++ > 5 files changed, 471 insertions(+), 0 deletions(-) > create mode 100644 arch/arm64/include/asm/device.h > create mode 100644 arch/arm64/include/asm/fb.h > create mode 100644 arch/arm64/include/asm/io.h > create mode 100644 arch/arm64/kernel/io.c > create mode 100644 arch/arm64/mm/ioremap.c > > diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h > new file mode 100644 > index 0000000..48fa83f > --- /dev/null > +++ b/arch/arm64/include/asm/io.h
[...] > +/* > + * I/O port access primitives. > + */ > +#define IO_SPACE_LIMIT 0xffff > + > +/* > + * We currently don't have any platform with PCI support, so just leave this > + * defined to 0 until needed. > + */ > +#define PCI_IOBASE ((void __iomem *)0) You could just leave out the PCI / I/O code alltogether instead. > diff --git a/arch/arm64/kernel/io.c b/arch/arm64/kernel/io.c > new file mode 100644 > index 0000000..7d37ead > --- /dev/null > +++ b/arch/arm64/kernel/io.c > @@ -0,0 +1,64 @@ > +/* > + * Based on arch/arm/kernel/io.c > + * > + * Copyright (C) 2012 ARM Ltd. > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see <http://www.gnu.org/licenses/>. > + */ > + > +#include <linux/export.h> > +#include <linux/types.h> > +#include <linux/io.h> > + > +/* > + * Copy data from IO memory space to "real" memory space. > + */ > +void __memcpy_fromio(void *to, const volatile void __iomem *from, size_t > count) > +{ > + unsigned char *t = to; > + while (count) { > + count--; > + *t = readb(from); > + t++; > + from++; > + } > +} > +EXPORT_SYMBOL(__memcpy_fromio); > + > +/* > + * Copy data from "real" memory space to IO memory space. > + */ > +void __memcpy_toio(volatile void __iomem *to, const void *from, size_t count) > +{ > + const unsigned char *f = from; > + while (count) { > + count--; > + writeb(*f, to); > + f++; > + to++; > + } > +} > +EXPORT_SYMBOL(__memcpy_toio); > + > +/* > + * "memset" on IO memory space. > + */ > +void __memset_io(volatile void __iomem *dst, int c, size_t count) > +{ > + while (count) { > + count--; > + writeb(c, dst); > + dst++; > + } > +} > +EXPORT_SYMBOL(__memset_io); Doing all of the above a byte at a time is horribly inefficient. Feel free to borrow the implementations from arch/powerpc/kernel/io.c instead of from ARM. -Olof -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
